The invention concerns a brush for the application of a cosmetic product. This brush is particularly adapted to the application of mascara to the eyelashes but can also be used for hair treatment, such as dyeing.
Generally, the brushes are made by implanting a plurality of bristles transversely on a core. This core can be in the shape of a plate. Another form of the brush core is formed by two branches of a helically twisted metallic wire, the bristles being fixed in the spirals formed by these twisted branches. This type of brush is very widely used for the application of mascara.
When a brush is provided with relatively soft bristles, only a small amount of the product remains on the bristles following the wiping which takes place when the brush is removed from the reservoir container of the product. The resulting make-up will be weak. Moreover, when the soft bristles are pressed down against the core, the eyelashes cannot enter between these bristles which lie on top of one another during the making up.
If the brush is provided with stiffer bristles, whether or not mixed with softer bristles, the stiffer bristles remain more heavily charged with the product after wiping, in particular if they are provided with capillary grooves. The interspacing between the bristles can be increased, thereby allowing the eyelashes to be well separated, but the quantity of the product deposited on the lashes is variable, in particular over the length of lash, and the make-up obtained is not always satisfactory, since the effect of the softer bristles is cancelled by the stiffer bristles.